Is Professor Moriarty right or left handed?

Answer 1

There is no specific mention of the handedness of Moriarty in any of the Holmes books. He is an infrequent character and seldom seen at the best of times. There is an indication that Doyle wished Moriarty to be the mirror image of Holmes - evil matching good, on the side of disorder where Holmes sought Law and Order - so it would be reasonable to assume Moriarty was the opposite handedness to Holmes. In "Was Sherlock Holmes Left-Handed? Or Spacial Intelligence and Creativity" Dalma Kalogiera-Sackellare postulated that Holmes was left handed based on his creativity, powers of observation and various artistic talents. This would imply a right handed Moriarty. This would be in line with Moriarty's mathematical abilities (Right handed, Mathematical- left brain)

On the the other hand Moriarty was sinister, and this would imply left handed person who, in popular culture, would be malicious or evil.